From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752550AbdF3Bp4 (ORCPT ); Thu, 29 Jun 2017 21:45:56 -0400 Received: from mga02.intel.com ([134.134.136.20]:40549 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752343AbdF3BpE (ORCPT ); Thu, 29 Jun 2017 21:45:04 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,283,1496127600"; d="scan'208";a="1188814427" From: "Huang, Ying" To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Minchan Kim , Rik van Riel , Shaohua Li , Hugh Dickins , Fengguang Wu , Tim Chen , Dave Hansen Subject: [PATCH -mm -v2 5/6] mm, swap: Add sysfs interface for VMA based swap readahead Date: Fri, 30 Jun 2017 09:44:42 +0800 Message-Id: <20170630014443.23983-6-ying.huang@intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170630014443.23983-1-ying.huang@intel.com> References: <20170630014443.23983-1-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huang Ying The sysfs interface to control the VMA based swap readahead is added as follow, /sys/kernel/mm/swap/vma_ra_enabled Enable the VMA based swap readahead algorithm, or use the original global swap readahead algorithm. /sys/kernel/mm/swap/vma_ra_max_order Set the max order of the readahead window size for the VMA based swap readahead algorithm. Signed-off-by: "Huang, Ying" Cc: Minchan Kim Cc: Rik van Riel Cc: Shaohua Li Cc: Hugh Dickins Cc: Fengguang Wu Cc: Tim Chen Cc: Dave Hansen --- mm/swap_state.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/mm/swap_state.c b/mm/swap_state.c index c88eda175ba7..bd483aff543a 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -812,6 +812,51 @@ static ssize_t swap_readahead_total_show( static struct kobj_attribute swap_readahead_total_attr = __ATTR(ra_total, 0444, swap_readahead_total_show, NULL); +static ssize_t vma_ra_enabled_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", swap_vma_readahead ? "true" : "false"); +} +static ssize_t vma_ra_enabled_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + if (!strncmp(buf, "true", 4) || !strncmp(buf, "1", 1)) + swap_vma_readahead = true; + else if (!strncmp(buf, "false", 5) || !strncmp(buf, "0", 1)) + swap_vma_readahead = false; + else + return -EINVAL; + + return count; +} +static struct kobj_attribute vma_ra_enabled_attr = + __ATTR(vma_ra_enabled, 0644, vma_ra_enabled_show, + vma_ra_enabled_store); + +static ssize_t vma_ra_max_order_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", swap_ra_max_order); +} +static ssize_t vma_ra_max_order_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err, v; + + err = kstrtoint(buf, 10, &v); + if (err || v > SWAP_RA_ORDER_CEILING || v <= 0) + return -EINVAL; + + swap_ra_max_order = v; + + return count; +} +static struct kobj_attribute vma_ra_max_order_attr = + __ATTR(vma_ra_max_order, 0644, vma_ra_max_order_show, + vma_ra_max_order_store); + static struct attribute *swap_attrs[] = { &swap_cache_pages_attr.attr, &swap_cache_add_attr.attr, @@ -820,6 +865,8 @@ static struct attribute *swap_attrs[] = { &swap_cache_find_total_attr.attr, &swap_readahead_hits_attr.attr, &swap_readahead_total_attr.attr, + &vma_ra_enabled_attr.attr, + &vma_ra_max_order_attr.attr, NULL, }; -- 2.11.0